Idea of Group Message Icon
The icon is a picture of group message. The icon is the shape of two rectangles. The rectangle in front of the other one looks like an envelope. The envelope looking rectangle is slightly lower and to the right of the rectangle behind it.
This Group Message icon is made in Material Design style
developed by Google. This style is based on extremely simplified shapes, thin two-pixel lines, and is optimized for 24x24 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 6,200 icons, all in the same style and quality.